期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1976
卷号：73
期号：4
页码：1009-1013
DOI：10.1073/pnas.73.4.1009
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：l-Isoproterenol was covalently coupled via an azo linkage to soluble copolypeptides of molecular weight 1500 and 10,000 containing an aromatic amine. The polymeric azo-isoproterenol derivatives were purified by gel chromatography which reduced contamination by the parent isoproterenol to undetectable levels (i.e., less than 0.01%) and by 6-aminoisoproterenol to less than 0.4%. Both polymeric isoproterenol derivatives were found to elicit positive chronotropic responses in isolated perfused guinea pig hearts. The mean effective doses (ED50S) for the 1500 and 10,000 molecular weight derivatives were within 1.3 and 2.0 orders of magnitude, respectively, of the ED50 of l-isoproterenol. The responses cannot be attributed to free isoproterenol because this drug could not be detected in our preparations. Neither can the observed biological activity be attributed to 6-aminoisoproterenol, since this compound's dose-response is shifted 3 orders of magnitude to the right of l-isoproterenol and 1-2 orders of magnitude to the right of the polymeric derivatives. Inotropic response decay times in isolated cat papillary muscles following washouts indicate that the polymer-bound drug does not diffuse into the muscle tissues. We feel that our findings demonstrate that under controlled conditions the catecholamines can retain biological activity while covalently bound to a polymeric support.
